Hand-shears for cutting metals or other hard materials in sheets.



No. 693,575. Patented Fab. l8, I902. a. THUILLIER.

HAND SHEARS FDR CUTTING METALS OR OTHER HARD MATERIALS IN SHEETS.

(Application filed Dec. 10, 1900.

(No Model.) 2 Sheets-$hoet I.

No. 693,575. Patented Feb. I8, I902. G. THUILLIER.

HAND SHEARS FOR CUTTING METALS OR OTHER HARD MATERIALS IN SHEETS.

(Application filed Dec. 10, 1900.)

2 Shaets- Sheat 2.

(No Model.)

NlTF STATES tartar e rrucn.

GEORGES TIIUILLIER, OF NOGENT-EN-BASSIGNY, FRANCE.

HAND-SHEARS FOR CUTTING METALS OR OTHER HARD MATERIALS IN SHEETS.

SPECIEIGATION forming part of Letters Patent No. 693,575, dated February18, 1902.

Application filed December 10,1900. Serial No. 39,312. (No model.)

To (all whom, it may concern:

Be it known that I, GEORGES THUILLIER,

manufacturer, a citizen of the Republic of France, and a resident ofNogent-en-Bassi guy, Haute-Marne, France, have invented new and usefulImprovementsin Hand-Shears for Cutting Metals or other Hard Materials inSheets, of which the following is a specification. The present inventionrelates to a kind of hand-shears which owing to the specialconfiguration of their cutting-blades permit of the cutting of hardsheet materialssuch as metals, leather, linoleum, cardboard, &c.- withequal facility in a curve of any form as in a straight line withouttwisting same. The two blades are provided with operating-handles andare articulated in the manner of ordinary shear-blades. Both blades arealike, and they are arranged symmetrically. Each of them is curvedlongitudinally and in transverse section presents such formapproximately lenticular as to present on the inner face a surfacecurved outwardly directly from the cutting edge and as to have itsgreatest thickness situated in a direction at a great in clination inrelation to the plane of the cut perpendicular to the axis ofarticulation of the blades. Owing to this construction the shears arecapable of cutting the most difficult curves without twisting ordistorting the sheet. 7

I will now proceed to describe my invention in connection with theaccompanying drawings, which illustrate an example of the improvedshears.

Figure 1 is an elevation of a pair of shears, the operating-arms ofwhich are of the ordinary form. Fig. 2 is a section, on an enlargedscale, through the line A A, Fig. 1. Figs. 3 and 4 are perspective viewsillustrating the action of the shears. Fig. 5 is an elevation showingthe shears in the working position. Fig. 6 is a horizontal sectionthrough line B B, Fig. 5. Figs. 7 and S are respectively a sideelevation and a plan view of shears only difiering from those shown inFig. 1 in the form and the arrangement of the operatingarms.

a and 3) indicate two cutting-blades, which are curved longitudinally,so that the angle which they form. at the cutting-point does not varyappreciably during the operation, which permits of the out beingeffected without any great variation of power or eifort throughout thewhole period of the closing movement of the two blades. In thetransverse section the two blades present the approximatelylenticularform indicated in Fig. 2, their greatest dimension or thickness being inthe direction of the line .2 e, which is at a great inclination inrelation to the cutting-plane as 00', and their inner surfaces curvingoutward directly from their cutting edges. These blades are absolutelysymmetrical in relation to the cutting-line 2510, which passes throughthe axis of articulation "a and the successive points of out, such as 0,Figs. 1 and 2. The blades thus formed are exceedingly firm or rigid,because their greatest thickness is in the direction in which they tendto bend. In fact the strain to which each blade is subjected may bedivided into two. These are, for the upper blade, for example, first,the reactionary force 0 cc, opposed to the movement of the blade, and,second, a strain 0 y, which owing to the resistance to the cut, tends toforce the blades asunder. Therefore it will be seen in Fig. 2 that thegreatest thickness of the blade is just in the direction of theresultant 0 z of these two forces 0 00 and o 3 Further, Figs. 3 and 4clearly show that owing to the special conformation of the blades theshears are capable of readily effecting a cut of any curvature withouttwisting the sheet of material. The reason of this is because the partof the sheet already out which is situated on the side of the line ofcut opposed to that of the center of curvature at the cutting-point canalways pass without any material distortion either under the lowerblade, Fig. 4, or over the upper blade, Fig. 3, the concave portion ofthe out portion turning around this blade, as indicated in Figs. 5 and6.

In order that the hand operating the shears may not be incommoded in itsmovements by the portions of the sheet already out which are situatedbeneath it, the operating-arms may be raised or bent upward, as shown inFig. 7. Further, in order that the part of the sheet already out whichrests upon the lower blade should not come into contact with theoperating-arms, and consequently that the shears may always move forwardwithout any obstacle, the two arms and handles are oltset laterally fromthe cutting-plane on the side of the upper blade, as shown in Fig. 8.

I claim 1. Hand-shears for cutting metals and other materials in sheets,composed of two symmetrical cutting-blades provided with operatingarmsand articulated in the manner of ordinary shear-blades, in which each ofthe blades is curved longitudinally and has a transverse section ofsuchapproximately lenticular form as to present on the inner face a surfacecurved outward directly from the cutting edge and as to have itsgreatest thickness situated in a direction at an inclination in relationto the plane of cut perpendicular to the axis of articulation of theblades, substantially as and for the purpose specified.

2. Hand-shears for cutting metals and other hard materials in sheets,composed of two symmetrical cutting-blades provided with opcrating-armsand articulated in the manner of ordinary shear-blades, in which each ofthe blades is curved longitudinally and has a transverse section of suchapproximately lenticular form as to present on the inner face a surfacecurved outward directly from the cutting edge and as to have itsgreatest thickness situated in a direction at an inclination in relationto the plane of cut perpendicular to the axis of articulation of theblades, and in which both the handles are raised and offset laterallyfrom the cutting-plane on the side of the upper blade, substantially asand for the pur pose specified.

In testimony that I claim the foregoing as my invention I have signed myname, in pres ence of two witnesses, this 23d day of Novem-- ber, 1 900.

GEORGES THUILLIER. WVitnesses:

THOMACHOT, RIERKEN.

